Do you have the original bearing in hand? If so, my experience has been that you may do better searching for that manufacturer part number that is likely stamped on the bearing itself. I have replaced several of the bearings on my car from a local bearing supplier.https://www.motionindustries.com/miLocations.jsp

I looked a Niemoller, but it looks like they don't stock it, but can get it.

One additional comment. The original bearing was lubricated by the Central Lube System. Many years ago, my bearing was replaced with a sealed bearing and that lube hose closed off. (Same thing with the bearing in the middle of the drive shaft.)

I have solved this problem by using a later MB release bearing and modifying the housing, using a special seal and some machining of the carrier. The set up gives you a sealed bearing which eliminates central lube oil from the clutch area. Contact me if you are interested in having this done.

I should say, however, that I worked this out because there was no bearing available at the time. I don't know what Niemoeller is currently offering, if anything. They may now have something that works well and is a direct install.